<Original Papers>Effects of Hydrofluoric Acid on Distribution of Cesium or Strontium between Zeolites and Aqueous Solutions

The distribution of Cs or Sr between zeolites and aqueous solutions has been studied by varying HF concentrations. The structure of zeolites was stable in HF≦0.1M, and the distribution coefficient K (ml/g) of Cs and Sr was above 10^4. Zeolites with low Si/Al ratios were converted to chiolite (Na_5Al_3F_14) by treatment in 1～3M HF solutions, and this product had the adsorption ability for Cs and Sr. The destruction of zeolite structures was appreciably depressed by the addition of masking agent H_3BO_3 (0.1M) into the HF solutions, and the Kc_3 and Ks_r values were enhanced above one order of magnitude